( Reaffirmed 2001 ) Indian Standard PROCEDURE FOR INSPECTION AND TESTING OF ALUMINIUM ALLOY FORGING STOCK AND FORGINGS FOR AIRCRAFT PURPOSES Light Metals and Their Alloys Sectional Committee, Representing Indian Aluminium Company Ltd, Calcutta SMDC 10 Chairman SHRI B. K. MU~THY Members SHBI V. D. AQARWAL SHRI V. K. A~EAWAL SHRI N. C. BACWHI SEW B. C. BISWAS ( Alternate ) Ministry of Defence ( DGI ) LT-COL G. K. BAIL SHRI K. L. CHAKRABORTY ( Alternate ) Ministry of Defence ( R & D ) DR V. CHANDRA~EKHAR SERI P. K. MAHAPATRA ( Alternate ) Premier Automobiles Ltd, Bombay SHRI D. M. DAVER SHRI A. T. BORATE ( Alternate) ( MET)-2, Ministry of Railways DIRECTOR DEPUTY RDSO, LUCKNOW STANDEPUTY DIRECTOR, DARDS ( CARR )-I, RDSO, LUCKNOW (Alternate I ) CHEMIST & METALLURGIST, Aluminium Corporation of India Ltd, Calcutta Hindustan Aluminium Corporation Ltd, Renukoot, Dist Mirzapur National Test House, Calcutta DEPUTY GENERAL M A N A Q E R Maharashtra State Road Transport Corporation, Bombay (ME) Indian Aluminium Co Ltd, Calcutta SEW N. GOPALKRISHNAN SHRI A. K. HAJRA ( Alternatc ) Larsen & Toubro Limited, Bombay SHRIB.JAC+ANNATHA RAO The Indian Standard Metal Co Ltd, Bombay SHRI F. A. A. JABDANWALLA SKRI C. CHATTERJEE ( Alternate ) Aluminium Industries Ltd, Kundara SHRI P. M. JOSEPH ( Continued on page 2 ) @ INDIAN Cofiyright 1975 INSTITUTION NORTH EASTERN RAILWAY, GORAKHPUR (Alternate II) STANDARDS This publication is protected under the Indian Copyright Act (XIV of 1957) and reproduction in whole or in part by any means except with written permission of the publisher shall be deemed to be an infringement of copyright under the said Act. IS : 7674 - 19% ( Continued from page 1 ) Members SERI K. K. KAPOOR SHRI SHRI Repesenting All India Non-Ferrous tion, Bombay Metal Industries Associa- w . J . FERN ANDES ( Ahnate ) Bharat Aluminium Company Ltd, New Delhi M. L. KAUL LT-COL 0. N. BHAN ( Alternate ) Ministry of Steel & Mines (Department of SHRI J. MARWAHA Mines ), New Delhi Electrical Mam&;;$ng Co Ltd, Calcutta SHRI 0. P. MATHUR Ordnance Factories Directorate SHRI D. Y. MOQIIE I Ministrv of Defedce II \. Calcutta ' SHRI S. M. R. SIN~H ( Alternate ) ' Heavy Electricals ( India ) Ltd, Bhopal SHRI M. S. S. MTJRTY SERI U. MOHAN RAO ( AEternate ) Hindustan Aeronautics Ltd ( Bangalore Division), DR KRISHNA DAS NAIR Bangalore SERI V. S. PATRIPAR ( Alternate I ) &RI K. G. BALAKR~SHNAN NAIR ( Alternate II ) India Government Mint (Ministry of Finance), SERI I?. M. RAU Calcutta The Institute of Indian Foundrymen, Calcutta SERI M. K. RAO HONY SECRETARY ( Alternate ) Eyre Smelting Pvt Ltd, Calcutta SHRI S. ROY SHRI A. K. BASU (Alternate) Directorate of Technical Development & ProducSERI U. SEN tion ( Air ), Air Headquarters Bharat Heavy Electricals Ltd, Hyderabad DR K. K. SENQO~AN SHRI B. N. BISWAS ( Alternate ) India Pistons Limited, Madras SHRI M. S. SESHADRI Jeewanlal ( 192Y ) Ltd, Calcutta SERI D. H. SHAH Madras Aluminium Co Ltd, Mettur Dam SHRI N. SHANMUQEAM Electrochemical Research Institute Central SHRI B. A. SEEN01 ( CSIR ), Karaikudi SRRI P. S: DESIKAN ( Alternate, I of Technical Development, SEEI B. P. SINXA Dire;;;; ,($neral e Directorate General of Supplies and Disposals, SERI K. M. TANEJA New Delhi SHRI K, L. MURTY (Alternate) National Metallurgical Laboratory _ ( CSIR ,. 1, DR Y. N. TREHAN Jamshedpur Director General, IS1 ( Ex-o&i0 Member ) .%RI C. R. RAMA RAO. Director ( Strut & Met ) Secretary SHRI S. L. BALI Deputy Director ( Metals), IS1 ( Continued on page 20 ) 2 IS:7674-1975 Indian Standard PROCEDURE FOR INSPECTION AND TESTING OF ALUMINIUM ALLOY FORGING STOCK AND FORGINGS FOR AIRCRAFT PURPOSES 0. FOREWORD 0.1 This Indian Standard was adopted by the Indian Standards Institution on 31 March 1975, after the draft finalized by the Light Metals and Their Alloys Sectional Committee had been approved by the Structural and Metals Division Council. 0.2 This standard has been prepared to cover general inspection and testing requirements for aluminium alloy forging stock and forgings used in aircraft and aeroengine manufacture. 0.3 In the formulation of this standard, due weightage has been given to international co-ordination among standards and practices prevailing in different countries in addition to the practices followed in the field in this country. This has been met by deriving assistance from the following specifications: AIR BS 905OC- 1960 Aluminium alloy products - Acceptance requirements. Association Francaise de Normalisation, France. 3LlOO-1971 Procedure for inspection and testing of wrought aluminium and aluminium alloys. British Standards Institution. aluminium Standartov, and aluminium alloy rods. Meri Izmeritelinyl Briborov. GOST 4783-1968 Extruded Gosudorstvenny Komitet ( SSSR ), USSR. 0.4 This standard contains clauses 3.2, 3.5, 3.6, 5.1.2, 6.1.1, 6.2.1, 6.7.3, 8.2.4.2, 9.3.1, 9.3.2, 10.1.1.1, and 10.3.2 which call for agreement between the manufacturer and the purchaser. 0.5 For the purpose of deciding whether standard is complied with, the final value, ing the result of a test or analysis, shall be IS : 2-1960*. The number of significant off value should be the same as that of the *Rules for rounding off numerical a particular requirement of this observed or calculated, expressrounded off in accordance with places retained in the rounded specified value in this standard! values ( revised ) . 5 1S :7674-1975 1. SCOPE 1.1 This standard covers procedure for inspection and testing of aluminium alloy forging stock ( bars, rods, sections and billets ) and forgings used for aircraft and aeroengine purposes. 2. TERMINOLOGY .2.0 For the purpose of this standard, the following definitions shall apply, 2.1 Bar -- A solid section whose width or greatest distance bet-ween parallel faces is greater than 6 mm. 2.2 Rod -- Any round solid section with a diameter 2.3 Section -- A length of extruded material neither bar as defined in 2.1 nor in the form of tube or wire. 2.4 Billet -- A cylindrical for subsequent hot-working. 2.5 Forging 2.6 Forging forging. -- A product Stock or rectangular of hot-working greater than 6 mm. covered by the term used cast or wrought by a hammer products or press. -- Bars, rods, sections and billets meant for subsequent 2.7 Harmfal Defects -- Any defect prejudicial to subsequent manufacture, fabrication or use of the material ( see Appendix A). 2.8 Draft -- The angle of taper given to the side wall of the clieimpression in order to facilitate removal of the forgings from the dies. 2.9 Off-Set ( Mis-match ) -- The displacement of a point in that part of a forging formed by the die block of a pair from its correct position when located from the part of the forging formed in the other die block of the pair. It is displacement in direction parallel to the parting plane of the dies and does not include any displacement caused by variation in the thickness of the forging, 2.10 Die Wear -- The erosion suffered on all surfaces of die impression during use, resulting in the progressive addition of an enveloping surface to the forging. 2.11 Fillet or Female Edge Radius -- The radius used to fill-in a female edge, thereby adding metal to the forging. 2.12 Male Edge Radius -- The radius used thereby removing metal from the forging, to round-off a male edge, 2.13 Inspector -- The individual responsible for the execution, inspection and release of material. This term shall be interpreted in any manner directed by the inspecting authority. 4 2.14 Inspecting Authority - The body manufacturer or supplier to issue certificate. responsible for authorizing 2.15 Inspection Schedule - A schedule of any special test requirements agreed upon between the manufacturer/supplier and the purchaser. 3. CONDITION AND FINISH unless otherwise stated in 3.1 The forging stock should not be heat-treated the drawing, order or inspection schedule. 3.2 Nonheat-treatable Alloy Forgings - Forgings alloys should be delivered in as-forged or annealed between the manufacturer/supplier and the purchaser. of nonheat-treatable condition as agreed 3.3 Heat-Treatable Forgings - Forgings of heat-treatable alloys should be delivered in the solution heat-treated and naturally aged or solution heat-treated and precipitation-treated condition according to material specification requirements unless otherwise stated in the order. 3.4 If appropriate, the drawing, order or inspection schedule should define the areas of forgi.ngs which are critical and for which special finish prior to inspection is required together with the standard of such finish. 3.5 The manufacturer and the purchaser should agree when a particular type of forging is to be partially or fully machined prior to heat treatment. Details of the agreement includiug the machining to be done by the manufacturer should be stated in the drawing, order or inspection schedule. 3.6 If agreed upon between the manuracturer and the purchaser and stated on the drawing, order or inspection schedule, the forgings should be coldcompressed. The permanent set should not be less than 1 percent nor more than 5 percent. 4. CERTIFICATION 4.1 The manufacturer should supply to the purchaser the certificates in respect of all material governed by this standard material specification. necessary and the 4.2 Except as provided in 4.3, if any certificate is issued by a supplier other than the manufacturer, such supplier should hold the equivalent certificate issued by the manufacturer of the material. 4.3 If a batch of material consigned by the manufacturer is subdivided by an approved supplier, before reconsignment, the supplier should carry out any consequent additional dimensional inspection and identification marking and should certify accordingly. is: ?674. 19% 5. MANUFACTURE AND FREED~Ni j?Rol&i bE~EC~~ with the 5.1 Manufacture -- The material should be made in accordance requirements of this standard and the material specificatirm. 5.1.2 In the case of forgings, if method of production has been agreed between the manufacturer and the purchaser, this should be stated in the drawing, order or inspection schedule and should not be altered except by mutual consent. 5.1.3 Forging approval procedure should be initiated in eases involving any significant change in the manufacturing process, that is, new design, change of material and alteration in forging techniques. 5.2 Freedom 5.2.1 from Defects A ). The material should be free from harmful defects (see Appendix 5.2.2 Any material should be rejected for faults in manufacture although it may have passed the chemical composition and mechanical tests. 6. DIMENSIONAL `6,1 Forging Stock TOLERANCES 6.1,1 Dimensional tolerances when required should be agreed to between the manufacturer and the purchaser and should be stated in the drawing, order or inspection schedule. -6.2 Forgings 6.2.1 Unless otherwise agreed to between the manufacturer and the order or inspection schedule, the purchaser and stated in the drawing, forgings should comply with the dimensional tolerances as in Tables 1 to 7. 6.2.2 The tolerances given in the tables should apply only to forgings of In the case of cQmplex design this standard tolerances may average form. form only a basis on which to agree modifications appropriate to the particular circumstances. 6.2.3 .Standard of accuracy in accordance with the tolerances may be If close achieved only by the use of really sound production techniques, tolerances are required it should be agreed to between the manufacturer and the purchaser. ,. 6.3 Thickness Tolerances 6.3.1 Table 1 indicates the permissible variation in any dimension which crosses the parting plane of the dies and should -be applied in a direction perpendicular to the main or fundamental parting plane. 6 IS : 7674 - 1975 TABLE 1 THICKNESS TOLERANCE FOR FORGINGS ( Cluuscs 6.2.1, 6.3.1 and 6.3.3 ) NET MASS c--_--*----_~ Over Up to and Including (1) (2) kg kg 0'10 THICKNESS TOLERANCE T__---*_--_7 Minus Plus (3) mm (4) mm 070 0.25 0.50 ;:"o 6.0 0.25 0.50 ::; 9":; O-5 0'8 ::p ;:5" 2.0 o-3 ;:; 0.3 0.5 0.5 6.3.2 For all forgings above 9 kg, the tolerances should be agreed to between the manufacturer and the purchaser. 6.3.3 Thickness tolerances on pressed forgings should be obtained by using only the plus figures from Table 1; the minus tolerances in each case being zero. 6.4 Width and Length Tolerances 6.4.1 Width and length tolerances should be applied to the width and/or length of a forging in a direction parallel to the main or fundamental parting plane of the die but only to such dimensions as one enclosed by, and actually formed by the die. 6.4.2 Width and length tolerances are subdivided into diewear and shrinkage and tolerances on centres (bosses ), off-set ( mis-match), etc. 6.4.3 Diewear and Shrinkage 6.4.3.1 Tolerances apply to any part of an impression in one die and apply to all surfaces not covered by thickness tolerances as given in Table 2. 6.4.3.2 Points of greater wear in the die should be permitted to increase to the limits given in Table 2, before the die is resunk. TABLE 2 TOLERANCES NET MASS r----Over k'g' OTO 0.25 0.50 ;:; 6.0 h----_-~ Up to and Including (2) 0% 0.25 0.50 1.5 6.0 3.0 9.0 (CCauses6.2.1, ON DIEWEAR (SURFACE) 6.4.3.1 and6.4.3.2) FOR FORGINGS DIEWEAR ( SURFACE TOLERANCE ) ~-----*.---_-_~ Plus Minus (3) mm 0.4 0.5 0.6 ;:9" ;:; (4) mm 0.1 0.1 0'1 0.1 0.1 7 IS : 7674 - 1975 6.4.3.3 A shrinkage tolerance of f 0'002 mm/mm should be applied irrespective of the size of the job and be added to the respective diewear tolerance and not applied separately. 6.4.4 Tolerances on Centres -Tolerances given in Table 3 should be used to maintain distances between boss centres etc, where it is desired. These tolerances should be applied independent of and should not be aggregated with, any other tolerances. 6.4.5 Of-set ( Mis-match ) Tolerances - When the need arises the off-set tolerances should be applied independent of and additional to any other tolerances. TOLERANCE ON CENTRES ( Clauses 6.2.1 and 6.4.4) TOLERANCE DISTANCEBETWEENBOSSES ._h______~ Up to and Including (2) (3) mm mm - TABLE 3 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 f 0.3 75 100 125 150 175 200 225 250 275 300 325 350 375 400 425 450 475 500 525 550 575 600 f0'4 5 0.5 f 0.6 -&o-7 5 0.8 f * f f f f f f f 0.9 1.0 1.1 1.2 1.3 I.4 1.45 1.5 1.6 & 1.7 & 1.75 & 1'8 i_ 1.9 & 2.0 f 2.05 k-t.1 For each additional 25 mm, increase f 2-l by 0.05 - 8 IS : 7674 -' lW5 TABLE 4 TOLERANCE NET Mass -----l Up to and Including (2) kg 0.25 ;.fJ 9.0 ON OFF-SET FOR FORGINGS OFF-SET TOLEBANCES MISPLACE~~ENT OF ONE DIE ( Classes6.2.1 and 6.4.5 ) y--_------h_-Over (1) kg 075 ;:; (3) mm 00:; 0'6 0.8 6.5 Draft Angles - In general, a nominal external draft angle of 5 to 7" and an internal draft angle of 7 to 10" are recommended. 6.6 Fillet and Male Edge Radii 6.6.1 The recommended radii in Table 5 are given only as a general guide as the most suitable radii for a particular forging may be arrived at only by a detailed study. TABLE 5 FILLET AND MALE EDGE RADII ( Clauses6.2.1 and 6.6.1 ) FILLETRADIU8, R mm 4'5 to 6.0 9.0 to 12.0 12'0 to 18.0 18'0 to 24-O 24.0 to 30.0 30.0 to 36.0 DEPTE, D mm 12.5 25'0 37.5 50.0 62.5 75.0 6.6.2 It should be noted that the relevant depth for the purposes of determining the fillet radius is the depth beyond which the metal has to flow from the intersection of the faces joined by the fillet as illustrated in Fig. 1. FIG. 1 DJAGRAW IIJXJSTRATING THE APPLICATION OF FILLET RADIUS DIMENSIONS 9 1S.r 7674 c 1975 6.7 Male Edge Radii 6.7.1 The recommended TABLE radii are given in Table 6. 6 MALE EDGE RADII ( Clauses 6.2.1 and 6.7.1 ) HEIGHT, H mm 12.5 37.5 62.5 75.0 MALEEDGERADIUS,R mm it5 ;:o" 6.7.2 It should be noted that the relevant height for the purpose of determining the male edge radius is illustrated in Fig. 2 by the relations of HtoR,HltoRr,H,toR,,andHatoRg. FIG. 2 DIAGRAMSILLUSTRATING THE APPLICATIONOF MALE EDGE RADIUS DIMENSIONS 6.7.3 Owing to side variations in design, tolerances on agreed fillets and male edge radii should be agreed to between the manufacturer and the purchaser. 6.8 Quantity Tolerance - The tolerances given in Table 7 should be the permissible over/under run allowed in each order. 7. CHEMICAL COMPOSITION 7.1 The chemical composition of the material should comply with the requirements of the material specification. The value stipulated in the specification should be applied in accordance with the instruction of the Inspection Authority. Elements not quoted in the specification should not be added for any purpose other than fluxing, degassing, grain-refinement and the like. The overall control of the chemical composition and the regulation for the use of scrap should be such that the method of analytical control adopted for each particular material should enable the inspector to certify compliance with the requirements. TABLE NVMBEB OB PIECESIN ORDER ( UP TO AND INcL~DINQ ) (1) 1: 300 I62 5000 10000 15000 20 000 Above 20 000 7 QUANTITY TOLERANCE ( Clauses 6.2.1 and6.8 ) QUANTITY TOLERAXCE ~____~___h~_~~~~~_~ Under-run Pieces Over-run Pieces (2) 6 4 :: 40 :: 300 400 500 (3) : 9 :: 50 E 7.2 The manufacturer should make an entry in his register of the melt and the chemical composition as and when regutar lots are melted. 7.3 Analysis of the alloys need be carried out on finished products only in the case of dispute. 8. SELECTION SAMPLES 8.1 Forging AND PREPARATION OF MECHANICAL TEST Stock 8.1.1 Billets - One billet from each batch of the same cast should be selected by the inspector for tensile test. 8.X.2 Bars, Rods and Sections - Bars, rods and sections of the same cast and manufactured by the same process should be grouped in batches as governed by Table 8. TABLE 8 SELECTION OF SAMPLES MAXIMUM SIZE OP BATCH NOMINAL DIAMETEROR MAJOR SECTIONAL DIMENSION C-----A-Over Upto Including (1) mm 10 20 50 (2) mm 10 20 (3) kg 5008 1000 1 500 2uoo - 50 *or 3 000 metres whichever is lesser in mass. 11 IS : 7674 - 19% 8.1.3 Processing 8.1.3.1Test samples from bars, rods and sections not greater than 30 mm diameter or minor sectional dimension, should be heat-treated if applicable in full section as per specification stifiulations and one test specimen* machined out coaxially to- the largest size as in Table 9. 8.1.3.2The inspector shall select one test sample section of the largest size in each batch for tensile test. from a batch or 8.1.3.3 Test samples from bars, rods and sections greater than 30 mm diameter or sectional dimensions should be heat-treated in full cross section, if applicable, and one test specimen machined out with its longitudinal axis halfway between the central axis and the outer surface of the test sample, to the largest practicable size as in Table 9. Alternatively, procedure in 8.1.3.4 should be followed. 8.1.3.4 Test samples from bars, rods and sections greater than 30 mm diameter or -mitror sectiontil dimension or bilets ( 8,l.l ) should be forged to not less than 39 mm or c+.Gvalent sectionsand subsequently heat-treated if applicable and .one test specimen machined out yoaxially to the largest practicable size &s'in Table 9. : TABLE 9 DIA PREPARATION 8.1.3.3, 8.1.3.4, OF TEST 8.2.5 SPECIMEN and 8.2.6) LENGTH (L,), Min (PI ( Clauses 8.1.3.1, NOMINAL CROSSSECTIONAL AREA (1) mm2 160 130 80 65 40 30 25 15 12 8 NOTE -By diameter other is 5.65 VK. .,,, 8.2.3.2, (4 GAUQE LENGTH (&,=5.65vz) PARALLEL (2) mm ! RADIUS SHOULDER, Min (5) mm 12'5 ' ll?l 9.0 8.0 6.5 5.5 5.0 4.0 3.5 3.0 `, (3) 70 64 51 46 36 32 29 23 20 17 -. mm 80 70 56 51 40 35 33 26 23 20 i4.0' 13'0 10.0 9.0 7.0 6.0 5.5 45 4.0 3.0 agreement with the Inspecting than those given in the table may Authority, test specimens with be used provided the gauge length *Rectangular test specimens should width, at the option of the manufacturer bc machined out with the maximum depending on the section shape. available 12 IS : 7674- 1975 8.2 Forgings* 8.2.1 Unless otherwise specified by the purchaser and stated on the order/ inspection schedule, procedures in 8.2.2 to 8.2.9 should be followed for selection and preparation of batch test samples. 8.2.2 The batches of forgings should be of the same cast and grouped for heat-treatment as governed by Table 10. , TABLE 10 SELECTION OF SAMPLES MAXIXUM NUMBER OIP FORQINQ~ IN A BATCH MASS OF FORGINGS c--_--A---_-~ Up to and Over Including (1) kg 0.75 1.50 5.00 25.00 (2) kg 0.75 1.50 5.00 25.00 - (31 2 000 1 000 400 200 As stipulated by the purchaser or stated in the order or inspection schedule 8.2.3 Separate Test Sample - Confined to forming the drawing of which do not call for cut-up test pieces from the body ( see also 8.2.4 ). 8.2.3.1 Three 250-mm lengths of forging stock from different pieces picked at random should be selected from the batch of the same cast used for forgings, and should be heat-treated in full section along with the forgings. 8.2.3.2 One test specimen from samples selected and heat-treated according to 8.2.3.1 and not greater than 30 mm diameter or minor sectional dimension should be machined coaxiallyt to the largest practicable size as per Table 9. 8.2.3.3 One test specimen from samples selected and heat-treated as per 8.2.3.1 and greater than 30 mm diameter or minor sectional dimension should be machined with its longitudinal axis halfway between the central axis and the outer surface of the sample ( to the largest practicable size in accordance with Table 9 ) . 8.2.3.4 Alternatively to 8.2.3.3 the bars and sections should be forged to 30 mm diameter and then heat-treated along with the forgings and one test specimen machined coaxially ( to the largest practicable size in accordance with Table 9 ). *It is rather difficult to specify mechanical test values which will represent accurately the mechanical properties of the forgings. Test samples other than those cut from the forgings indicate only the quality of the material and not exactly that of the forging. TRectangular test specimens should be machined out with the maximum width at the option of the manufacturer depending on the section shape. available 13 is : 7674 - 1915 0.2.4 Integrally Forged Test Samples for Cut-up Test 8.2.4.1 Alternatively to 8.2.3, a minimum of three integrally forged test samples should be selected for batch acceptance test. 8.2.4.2 Separation of integrally forged test samples from the body before or after heat treatment should be the subject of agreement between the manufacturer and the purchaser, but at least one test sample integral, with the forging that is, without separation should be one of the three test samples heat-treated in one batch and the one to be machined coaxially for test. 8.2.5 Forgings for which no separate or integral test samples are available initially or for retest, test specimen(s) should be machined out from the body of the forging at location(s) and direction ( to the largest practicable size in accordance with Table 9 ) indicated by the purchaser unless otherwise stated in the drawing/inspection schedule. 8.2.6 No separate test sample need be selected from batch of forgings whose drawings/inspection schedule called for cut-up test pieces in locations indicated in the body bf the forging in which case one set of test specimens should be machined (to the largest practicable size in accordance with Table 9 ) from the heat-treated forging. 8.2.7 When there is any significant change in the manufacturing process originally agreed upon, the manufacturer should select a forging from the proto-type production and machine out test specimen(s) from locations and direction indicated in drawing, order or inspection schedule or by the purchaser, and forward the test results to the purchaser for approval before starting production. 8.2.8 Test samples when separated from the forging stock or forging should be identified as directed by the inspector and the identification should be transferred on machining, processes, etc. 8.2.9 Manufacturer should provide the required number of test samples separate or integrally forged, along with the forgings if supplied without heat treatment and should advise heat treatment schedule to be followed. 9. MECHANICAL 9.1 Tensile Test TESTING 9.1.1 Forging Stock - One test specimen machined out of the test samples selected and heat-treated as in 8.1 when tested in accordance with IS : 1816- 1961* and should satisfy the tensile test requirement of the material specification. 9.1.2 Forgings 9.1.2.1 One test specimen from each batch machined out of the test samples selected and heat-treated along with the forgings in 8.2.3 *Method for tensile test for light metals and their alloys, 14 IS: 7674-1975 or 8.2.4 when tested in accordance with IS : 18 16-1961* and should satisfy the tensile test requirement of the material specification if the requirements are not stated in the drawing or inspection schedule. 9.1.2.2 If the drawing or inspection schedule calls for a set of test specimens ( 8.2.5 ), one set of test specimen(s) machined should be tested in accordance with the requirements of IS : 1816-196 I* and should satisfy the strength requirements as stipulated for individual test specimens in the drawing or inspection schedule. 9.1.2.3 Normally the minimum of 20 percent reduction in elongation in specimens taken in long transverse direction and 10 percent reduction in tensile and proof stress values with 50 percent reduction in elongation in short transverse direction may be expected from the values of specimens taken in longitudinal direction. 9.2 Retests 9.2.1 If any test specimen tested in accordance with 9.1.1 or 9.1.2.1 fails to satisfy the requirements of .-the material specification, further two test specimens machined out from the remaining test samples either of the in ` as is ' condition or after ` heat treatment ' at the discretion manufacturer and tested should satisfy the requirements of the material specification. 9.2.2 In case of non-availability of extra test samples for retests, two test specimens machined out from two forgings picked up at random in ` as is ' condition or after reheat treatment at the discretion of the manufacturer, from a location and direction indicated in the drawing or inspection schedule or indicated by `the purchaser, should satisfy the requirements of the material specification. 9.2.3 If the set of test specimens in 9.1.2.2 fails to satisfy the requirements of the drawing or inspection schedule, two further tests of test specimens should be machined out from two forgings picked up at random in ` as is ' condition or after reheat treatment at the discretion of the manufacturer and tested, which should satisfy the individual requirements of the test specimens indicated in drawing/inspection schedule. 9.3 Hardness Test 9.3.1 Unless otherwise agreed to between the manufacturer and the purchaser with the concurrence of the inspecting authority, each forging and representative tensile test piece should be hardness tested. 9.3.2 The hardness number of each forging should be not less than (a) that stipulated in the material specification, or (b) the minimum agreed to between the manufacturer and the purchaser and stated in the *Method for tensile test for light metals and their alloys. IS : 7674 - 1975 drawing, order or inspection schedule, or (c) the minimum the manufacturer and the inspecting authority. 9.3.3 agreed to between Retest 9.3.3.1 If any forging fails to satisfy the hardness test, the inspector should allow the forgings of incorrect hardness to be reheat-treated and retested in accordance with 9.2.1 and 9.2.2. 9.4 Other Tests ( Fatigue, etc ) (Applicable to Forgings Satisfied the Tensile and Hardness Requirements ) Which Have 9.4.1 When drawing or inspection schedule call for additional special such as fatigue tests ( vibration/flexural/rotating bendingltensiontests etc ) bending, stress rupture test, the machined forgings or compression, cut-up test specimens, as applicable should be tested accordingly by the inspecting authority and should satisfy the specific requirements. 9.4.2 If the tests in accordance with 9.4.1 fails to satisfy the requirements, at the discretion of the authority, two further tests may be carried ' condition at the option of the manuout in ` as is ' or ` reheat-treated facturer. 10. SPECIAL TESTS Test 10.1 Etching 10.1.1 Fdrging Stock 10.1.1.1 During each single working period, a specimen of each size of bar or section produced should be selected. Each specimen should be of full cross section and should be taken from the back and of the extruded The specimen should be length or from the front end of the final discard. solution-treated in accordance with the material specification suitably The etched surface should be free from harmful prepared and etched. defects. When examination of the front end of the selected bar or section is required, the details should be agreed to between the manufacturer and the purchaser and should be stated on the order or inspection schedule. NOTE - The permissible depth of coarsely crystalline structure agreement between the manufacturer and the purchaser. may be limited by 10.1.2 Forgings 10.1.2.1 Forgings should be sectioned in plane(s) indicated in the drawing if called for and should be macro-etched after suitable polishing, and should satisfy grain-flow requirements of the drawing. Grain-flow orientation which will cause fracture when the part is machined to its final outline, or any abnormal orientations which are not compatible with the stresses met in service, are to be considered defective. The etched surface should be free from any harmful defects such as re-entrants, inclusions, `cracks, blow holes, discontinuities, termination of grain fibres in the fillets, etc. 16 IS: 7674-1975 10.1.2.2 All the forgings etched in full, should not show any discontinuities such as fold, crack, laps, blisters, etc. NOTE -- All parts after etching should be cleaned thoroughly in running water to remove traces of etching reagents completely, dried and protected suitably. 10.1.3 Retest 10.1.3.1 If the forging stock tested in accordance with 10.1.1 fails in the etching test, another section in the same bar after cropping off sufficient length should be etched and when tested it should satisfy the requirements. 10.1.3.2 If the forgings tested in accordance with 10.1.2 fail to satisfy the requirements of the drawing and freedom from harmful defects, two further forgings should be examined in full or after sectioning as applicable and should satisfy the requirements of the drawing and freedom from harmful defects, 10.2 Texture Examination ( Confined to Forgings, the Drawings for Which Specifically Call For it) -- The fractured surfaces on fracturing in accordance with the drawing should be free from harmful defects ( see Appendix A). 10.3 Nondestructive Testing 10.3.1 Radiografihic Examination -- Billets for forging should be radiographer and should show freedom from harmful casting defects. 10.3.2 Ultrasonic Testing -- If the purchaser requires the material to be examined by ultrasonic inspection in the condition in which it is to be delivered, details of such method of examination and standard of acceptance should be agreed to by the manufacturer and stated on the order or inspection schedule. 10.3.3 Dye-Penetrant Check -- This check should be made on the forgings if required by the purchaser and stated on the order. 10.4 Micro-examination -- The sample(s) selected by the inspector should be micro-examined. It should show satisfactoryy structure, free from harmful defects such as heat deterioration effects ( eutectic melting, grain et c ) inclusions, boundary cracking, oxidation in the grain boundaries, heterogenity, etc. 11. REWORK 11.1 If the forgings get distorted after quenching during solution treatment, they may be corrected by strais@tcning, gentle mallet blows or use of hand press, in the as quenchecl concllticn that is within two hours, with the mutual agreement of the manufacturer and the purchaser, subject to thorough inspection f~r any external or internal defects resulting from such rework, 17 IS : 7674 - 1915 11.2 Surface cracks or laps detected on the surface of forgings may be removed by chiselling or grinding but within the dimensional tolerances. 12. IDENTIFICATION 12.1 The forging stock over 20 mm major sectional dimension, passed by the inspector should be stamped on or near their end and forgings over 2'5 kg, vibro-etched* with the inspector's number and such other numbers/ letters and should ensure full identification of the material. 12.2 Unless order requires, individual identification of the bars and sections less than 20 mm diameter or major sectional dimension or forgings less than 2'5 kg should be bundled together and attached with a durable label with necessary identification. 13. CORROSION PREVENTION suitable 13.1 Identified forging stock and forgings should be coated with temporary protectives to prevent corrosion in storage, transit, etc. AP_PENDIX A ( Clauses 5.3,5.2.1 and 10.2 ) GENERAL DEFECTS ENCOUNTERED IN ALUMINIUM ALLOY FORGING STOCK STOCK A-l. FORGING A-l.1 Surface Defects - On visual examination, surface of the bars, rods and sections should be clean and free from cracks, blisters, blow holes, laminations, metal sticking, severe corrosion pits, etc. of the bars, rods A-l.2 Structural Defects - Macro- and micro-structures and sections should not show any severe heterogenity, cracks, piping, laminations, folds, seams, non-metallic inclusions and other discontinuities and heat-deterioration ( eutectic melting, grain boundry cracking, rounding of constituents ). A-2. FORGINGS STOCK ( BILLETS ) A-2.1 Surface Defect - The cast billets for forging should be fret from casting defects, such as cracks, cold shut, non-metallic inclusion, blisters, blow hole, metal run-out, pipe, shrinkage, corrosion, etc. *Identification markings should be made in the location indicated on the drawing if it is called for, Ii? IS : 7674 - 1975 A-2.2 Structural Defects - The radiographic examination of the billets should not show any casting defects, such as non-metallic inclusions, shrinkage cavities, blow holes, pipes, severe segregation, etc. A-3. FORGINGS A-3.1 Surface Defects A-3.1.1 The forgings should be free from dents, nicks, cracks, blisters, blow holes, die marks, laminations, wearing, metal sticking, corrosion pits, laps, folds, etc, which exceed the maximum deviation Corn the nominal dimensions. A-3S.2 The forgings may be gently dressed to remove minor surface defects within the dimensional tolerances. A-3.2 Structural Defects - Micro- and macro-structure of the forgings shall be free from severe structural heterogenity, non-metallic inclusions, cracks, improper grainflow ( re-entrants, grain fibres terminating in the fillets, etc ), fold, lap, spongy areas, etc, discontinuities, and heat-deterioration ( eutectic melting, grain boundry cracking, rounding of constituents ). IS : 7674- 1975 ( Continued from page 2 ) Aircraft Materials Subcommittee, Con uener SHRI K. B. GANESAN Members SHBI G. K. AQARWAL SHRI V. D. ACARWAL SERI V. K. AGRAWAL SMDC Representing 10 : 2 Civil Aviation Department ( Ministry and Civil Aviation ), New Delhi of Tourism Indian Airlines Corporation, New Delhi Aluminium Corporation of India Ltd, Calcutta Corporation Ltd, Hindustan Aluminium Renukoot, Distt Mirzapur Hindustan Aeronautics Ltd ( Kanpur Division), FACTORY MANAQER Kanpur QUALITY CONTROL MANAQER ( Alternate ) Indian Aluminium Company Ltd, Calcutta SHRI B. K. MURTHY SHRI N. GOPALAKRISHNAN (Alternate) Hindustan Aeronautics Ltd ( Bangalore Division ), DR KRISHNA DAS NAIR Bangalore SHRI V. S. PATRIKAR ( Alternate I ) SHRI K. G. BALAKRISHNAN NAIR ( Alternate II ) Laboratory ( CSIR), SHRI S. RADHAKRISHNA National Aeronautical Bangalore Directorate of Technical Development & SHRI U. SEN Production ( Air ), Air Headquarters